SWI Prolog 9.1.11
SWI-Prolog offers a comprehensive free Prolog environment. It has been in development since 1987 and extended for requirements of real world applications, but is also widely used in research and education. It includes a nice command line interface, fast and transparent compilation, a debugger, profiling features. It also has the ability to integrate with C code, and already comes with packages for threading and process management, encryption, TCP/IP, TIPC, ODBC, SGML/XML/HTML, RDF, HTTP, graphic